A British reporter has uncovered a secretive Scientology site he says is an 'alien space cathedral' that includes a massive message to UFOs.

The site, located in northeastern New Mexico, houses the writings of the shadowy religion's founder, L. Ron Hubbard, in a titanium-sealed bunker built to withstand a nuclear blast, BBC Panorama reporter John Sweeney writes in his new book.

An excerpt from Sweeney's book, "Church of Fear: Inside the Weird World of Scientology," appeared in Britain's The Sun newspaper.

In the book, Sweeney -- who is well known for exploding on a Scientology flack during a 2007 investigation for BBC One's Panorama, a "60 Minutes"-style program in Britain -- writes that the Trementina Base is inscribed with two giant interlocking circles, each with a diamond inside.

The creepy crop circles are a salute to space creatures, and also act as a marker to "guide Clears, (high-ranking Scientologists) returning from space to find Mr Hubbard’s works after a nuclear Armageddon wipes out humanity," Sweeney writes.

"Its vault houses the lectures of church founder L Ron Hubbard on gold discs locked in titanium caskets sealed with argon," the excerpt says. "The cathedral is H-bomb proof, protected by three 5,000lb stainless steel airlocks."